Double seated valve



IIH III IIH Ill INVENTOR.

JOHN S. LESLIE ATTORN EYS Patented Jul 6, 1954 I 2,682,891

UNITED STATES PATENT OFFICE DOUBLE SEATED VALVE John S. Leslie, Ramsey, N. J., assignor to Leslie 00., Lyndhurst, N. J., a corporation of New Jersey Application November 10, 1949, Serial No. 126,467

1 Claim. (01. 137625.36)

- 1 2 This invention relates to valves and more parreceived in a suitable guide 20 formed in the L, ticularly to double acting valves. valve casing. For many purposes a double acting valve is The valve stem extends through a casting 3i! theoretically superior to a single acting valve. arranged on the top of the valve casing and may This theoretical advantage is, however, ofiset be provided with an operating handle 32. A packby the practical difficulty of constructing a valve ing gland 34 may surround the valve stem.

in which both valve members will properly en- In the form of the invention shown in the gage their seats throughout the range of temdrawing, at a distance above the valve member peratures, or temperatures and pressures, to 36, the stem is provided with a reduced portion which the valve is subjected in use. 11 4| forming a shoulder 42. The upper portion Upon changes in temperature, the expansion of the stem is further reduced as at 43 forming or contraction of the valve casing in which the a shoulder 44. A valve member 45 is slidably valve seats are formed or mounted may be greater m u t d o t e p tio 4| O t V v Stemor less than the expansion or contraction of the A disc 46 is rigidly mounted on the valve stem valve stem on which the valve members are 15 in contact with the shoulder 44 and held in posimounted. As a result, the two valves of a double tion by any suitable means, such as welding. acting valve which will close properly under one The disc 46 and the valve member 45 are conset of conditions, may not function properly nected by abellows member 41. The valve memunder another set of conditions. her is provided with one or more ports 48 through In order to obtain the advantages of a double which the fluid may enter the space between the acting valve without this disadvantage, I provalve member and the disc, thereby enabling pose to provide a construction in which one of the fluid to exert its pressure on both sides of the valves is yielding. The range through which the valve member. A coil spring 49 may also the yielding part may move is suflicient to combe arranged between these two members. The pensate for any differences that may be created 23 relative areas of the valve member 36 and the in the distance between the valves and the disvalve member 48 subjected, respectively, to the tance between the seats in the temperature and inlet an outl pr u r su h that a subpressure ranges in which the valve is used. stantially-balanced pressure on said valves is ob- In use, the valve member that is capable of tained. yielding will engage its seat first under all condi- The operation of this form of the invention tions and the closing of the valve is then conwill be apparent. Inan ordinary construction of tinued until the other valve member has also a double acting valve if, by expansion or conengaged its seat. Thus, the two valves will be traction, the distance between the valve seats closed to prevent any leakage regardless of the and the distance between the valve members temperature and/or pressure at which the closshould vary, when an attempt is made to close ing is eifected. the valve, one or the other of the valve mem- In the preferred form of the invention one of hers would engage its seat first and it would the valve members is yieldingly mounted on the then be impossible to move the valve any furvalve stem and it is so constructed that a subther to effect closing of the other valve member. S t y c d pressure is obtained at all in In the valve shown in the drawing, the distance times. from the seat at the top of the outlet I2 and Inthe accompanying drawing Ihave shownone the seat of the valve is such that under all embodiment of the invention. conditions the valve member 45 engages its seat Referring to the drawing, the reference nubefore the valve member 36 engages its seat. Due

meral 2 designates generally a valve casing hav- 5 to the fact that the valve 45 may yield becauseing an inlet 4 and an outlet 6. Both the inlet of the provision of the bellows 41, closing of and outlet are internally threaded to receive suitthe valve is continued until the valve 36 engages able connections. Within the valve casing I its seat. The bellows member 4'! may be formed provide a casting 8 having aligned openings I6 of metal having sufiicient spring to normally reand I2 to form the valve seats. The valves are tain the valve member at the maximum distance mounted on a valve stem 31, the lower or outer from the disc 46. Then, upon closing of the valve 36 being of conventional construction and valves, the valve member 45 engages its seat engaging a bevelled portion at the inner end of before the valve member 36 engages its seat. the opening [2. Beyond the valve 36 the valve Further movement of the valve stem compresses stem is extended and the lower portion 38 is the bellows member 41 until the valve member 36 engages its seat. The necessary spring may be built into the bellows member 41 or its action may be augmented by the spring 49, if desired. The provision of the ports 48 permits the steam or other fluid to enter the space between the disc and the valve member. Thus, pressure is exerted upwardly on the disc and on one side of the bellows construction and downwardly on the valve member and on the other side of the bellows construction thereby producing a substantially balanced eifect.

I 'claim:

A double acting valve comprising a casing having an inlet opening arrd an outlet opening, a pair of aligned openings in the casing to permit communication between the inlet and outlet openings, each of said openings forming a valve seat, a valve stem extending through the aligned openings, a rigidly mounted valve on the stem cooperating with one of the valve seats, a second valve member slidably mounted on the valve stem and co-operating with the second valve seat, a disc secured to the valve stem adjacent the second valve member, and a bellows member con meeting the second valve member and the disc, the second valve member having openings extending therethrough from one side thereof to the space within the bellows to permit fluid to flow from said one side into said space, whereby the fluid will exert its pressure on both sides of said second valve, the space within said bellows being closed to the passage of fluid except through said openings, the relative areas of the firstmentioned valve and the second valve subjected, respectively, to the inlet and outlet pressures being such that a substantially-balanced pressure on said valves is obtained, and the second valve member being mounted on the valve stem at a distance from the rigidly-mounted valve such that it will engage its seat before the rigidlymounted valve engages its seat.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 50,443 Bristol Oct. 17, 1865 208,986 Patterson Oct. 15, 1878 339,809 Putnam Apr. 13, 1886 463,175 St. John Nov. 17, 1891 723,894 Michael Mar. 31, 1903 763,208 Robinson June 21, 1904 967,820 Nachtigall Aug. 16, 1910 1,004,494 Stumpf Sept. 26, 1911 1,622,151 Joyce Mar. 22, 1927 2,243,863 Hoy June 3, 1941 FOREIGN PATENTS Number Country Date 9,182 Great Britain 1905 786,524 France 1935 

